1. Technical Field
The present invention relates to a liquid ejecting device and a method of controlling a liquid ejecting device, and more particularly, to a liquid ejecting device that has a head unit group in which a plurality of head units is arranged in a direction perpendicular to a direction, in which the head unit having a nozzle group formed by aligning a plurality of nozzles that eject liquids and a landing target relatively move with each other, and is configured to eject liquids without moving the head unit group in the direction of arrangement of the head units and a method of controlling the liquid ejecting device.
2. Related Art
Liquid ejecting devices are devices that have a liquid ejecting head for ejecting a liquid and eject various types of liquids from the liquid ejecting head. As a major liquid ejecting device, for example, there is an image recording device such as an ink jet printer that performs a record operation by ejecting (emitting) and landing ink having a liquid phase to a landing target such as a recording sheet. In addition, recently, the liquid ejecting device is not limited to the image recording device and is applied to various types of manufacturing apparatuses. For example, in an apparatus for manufacturing a display such as a liquid crystal display, a plasma display, an organic EL (Electro Luminescence) display, or an FED (Field Emission Display) the liquid ejecting device is used for ejecting various types of materials such as a coloring material or an electrode having a liquid phase to a pixel forming area, an electrode forming area, or the like.
An ink jet recording device (so called a printer) that is one type of the liquid ejecting devices has an ink jet recording head (one type of a liquid ejecting head that is so called a serial head) that is shorter than the width of a recording medium, a head moving mechanism that reciprocates the record head in the main scanning direction, and a transport mechanism (recording medium transporting mechanism) that performs a sub scanning operation by sending the recording medium (landing target) such as a recording sheet in the direction perpendicular to the main scanning direction, and the like. The ink jet recording device is configured to record an image or the like in the recording medium by alternately repeating ejection of ink droplets in the main scanning of the record head and transporting (sub scanning) of the recording medium. However, since there is a limit in the scanning speed of the record head, there is a problem in a device of this type that a long time period is needed, for example, in a case where an image is recorded on the entire surface of the recording medium that has relatively large size.
Thus, recently, a configuration in which head unit groups formed by arranging a plurality of head units in a second direction perpendicular to a first direction, in which head units having a nozzle group configured by aligning a plurality of nozzles and a landing target relatively moves from each other, are included and the head unit group ejects ink in a state that a record head (one type of line-type liquid ejecting head, and hereinafter, abbreviated as a line-type head) configured to be able to respond to a maximum record width of a recording medium is fixed without being moved with respect to a device main body has been proposed (JP-A-6-183029 (FIGS. 2 to 4)). According to such a configuration, movement of the record head in the main scanning direction is not needed, and, for example, recording an image or the like can be performed by transporting the recording medium only in the sub scanning direction. As a result, according to the configuration, a record time can be shortened, compared to a configuration using a serial head.
In addition, a printer having a configuration in which a plurality of ejection stages (record stages) is disposed along the transport direction of a recording medium, a transport unit formed of an endless belt (transport belt) transporting the recording medium or the like and a record head are included for each ejection stage, and an image of the like is sequentially recorded on the recording medium by using the record head of each ejection stage with the recording medium sequentially transported to each ejection stage by the transport unit has been proposed.
For example, as shown in FIG. 14, there is a configuration in which record heads 51a to 51d corresponding to colors of black (K), cyan (C), magenta (M), and yellow (Y) are disposed in ejection stages 52a to 52d along the transport path of a recording sheet 54 and an image or the like is formed in the recording sheet 54 for each color while the recording sheet 54 is transferred among transport belts 53a to 53d of the ejection stages. In the transport belt in each ejection stage, a linear scale 55 and a linear encoder 56 having a sensor unit that optically detects the scale pattern of the linear scale 55 are disposed, and a record operation is controlled based on a detection signal output from the linear encoder 56.
Under such a configuration, there is a case where the transport speed of the recoding sheet 54 changes due to a mechanical error of a transport unit including the transport belt or the like. In addition, in transferring the recording sheet 54 among the transport units of the ejection stages, the position of the recording sheet 54 in the direction (direction of alignment of the nozzles) perpendicular to the transport direction may be deviated. The transport error may cause the deviation of ink landing positions in the recording sheet 54 among the ejection stages. As a result, there is a possibility that the image quality of the image recorded in the recording sheet 54 deteriorates. In addition, when a print operation is performed by moving the line-type record heads 51a to 51d in the print direction without transporting the recording sheet 54 in the transport direction, if the recording sheet 54 is deviated in the print direction, the landing position of ink in the recording sheet 54 may be deviated. As a result, there is a possibility that the image quality of the image recorded in the recording sheet 54 deteriorates, as in the above-described case in which the recording sheet 54 is transported.
Here, when the position of the recording sheet 54 is deviated in the direction of alignment of nozzles, in a case where the record head is configured to be able to reciprocate in the direction of alignment of nozzles, the deviation of landing positions of ink in the recording sheet 54 in the direction of alignment of nozzles can be corrected by ejecting ink after adjusting the position of the record head in accordance with the amount of the deviation of the recording sheet 54. However, in a line-type head that is not moved relative to the device main body in a direction perpendicular to the transport direction of the recording sheet 54, the correction of the deviation of the landing positions cannot be made by moving the head.
In order to correct the deviation of landing positions in the direction of alignment of nozzles in the printer using the line-type head, a method in which the nozzle that ejects ink is changed in accordance with the deviation of the recording sheet 54 may be considered to be used. However, in such a case, a process for re-expanding ejection serial data for transmitting data to each head unit constituting the line-type head and the like becomes complex, and thereby there is a possibility that the process is delayed depending on the operation frequency of the ejection operation.